This invention is directed to the field of auxiliary power sources connectable to a primary power source having a rotating drive shaft. More particularly, the invention is concerned with apparatus for easily, releasably connecting an external mechanical load to the drive shaft of the power source, while reliably transmitting drive to the mechanical load.
The invention has particular application in connection with lawn and gardening devices which use engines having rotating drive shafts for operating a primary mechanical load, such as a rotating blade or the like. An example of such an application is the connection of a trimmer having a rotating operating member to the drive shaft, for example, a rotary lawn mower.
Power take-off attachments of this type in the prior art are typically connected to the bottom of the lawn mower crank shaft by a pulley or belt arrangement or through the use various forms of gears and levers. It is the usual case that such attachments have to be installed on the lawn mower or the like during the original manufacture of that device because the connection in question to the crank shaft, at its bottom end, will be relatively complex.
It is important to note that the usual form of prior art device of this type is directly connected to the source of power and there is no means provided for operating the secondary or auxiliary load, such as the trimmer, at a location some distance away from, for example, the rotary mower.
In the limited circumstances, such as in U.S. Pat. No. 4,242,855 where a flexible drive shaft is provided to allow an operator to use a trimmer away from the mower, the connecting mechanism between the drive shaft and the driven shaft is of relatively complex construction, difficult to connect and disconnect and not readily adaptable to existing mower drive shaft structures.
It is, therefore, an object of this invention to provide an auxiliary power unit connectable to the primary power source which is of simple construction and is easily connectable and disconnectible.
It is another object of this invention to provide such an auxiliary power source which can readily be used with existing drive shaft structures.
Another object of this invention is to provide a simple and easily operable assemblage of parts which may be readily utilized with the existing structure of a drive shaft in a rotating power source to accomplish the foregoing objects.